Yeast-derived nanoparticles remodel the immunosuppressive microenvironment in tumor and tumor-draining lymph nodes to suppress tumor growth

Microbe-based cancer immunotherapy has recently emerged as a hot topic for cancer treatment. However, serious limitations remain including infection associated side-effect and unsatisfactory outcomes in clinic trials. Here, we fabricate different sizes of nano-formulations derived from yeast cell wall (YCW NPs) by differential centrifugation. The induction of anticancer immunity of our formulations appears to inversely correlate with their size due to the ability to accumulate in tumor-draining lymph node (TDLN). Moreover, we use a percolation model to explain their distribution behavior toward TDLN. The abundance and functional orientation of each effector component are significantly improved not only in the microenvironment in tumor but also in the TDLN following small size YCW NPs treatment. In combination with programmed death-ligand 1 (PD-L1) blockade, we demonstrate anticancer efficiency in melanoma-challenged mice. We delineate potential strategy to target immunosuppressive microenvironment by microbe-based nanoparticles and highlight the role of size effect in microbe-based immune therapeutics.

Kidney-Draining Lymph Node Fibrosis Following Unilateral Ureteral Obstruction

Although the primary organ has been the subject of intense investigation in the field of organ fibrosis over the past several decades, the presence of lymph node fibrosis due to persistent activation of the immune response in its partner organ remains largely unknown. Previously, we demonstrated that activation of the immune response following ischemia-reperfusion injury (IRI) and crescentic glomerulonephritis (CGN) in the kidney was associated with extracellular matrix (ECM) production by fibroblastic reticular cells (FRCs) of the kidney-draining lymph node (KLN). Here, we sought to determine whether FRCs in the KLN become similarly fibrogenic following unilateral ureteral obstruction (UUO) of the kidney. We subjected 6–8-week-old C57BL/6J mice to UUO for 2, 7, and 14 days. We examined the microarchitecture of the kidney and KLN by immunofluorescence staining at each timepoint, and we quantified immune cell populations in the KLN by flow cytometry. The contralateral kidney unaffected by UUO and its partner KLN were used as controls. We found through immunofluorescence staining that FRCs increased production of ECM fibers and remodeled the microarchitecture of the UUO KLN, contributing to fibrosis that mirrored the changes in the kidney. We also observed by flow cytometry that the populations of CD11b+ antigen-presenting cells, CD11c+ dendritic cells, and activated CD4+ and CD8+ T cells were significantly higher in the UUO KLN than the KLN draining the unaffected contralateral kidney. Expression of the TGFβ/TGFβR signaling pathway was upregulated and colocalized with FRCs in the UUO KLNs, suggesting a possible mechanism behind the fibrosis. Both release of ureteral ligation at 2 days following UUO and depletion of FRCs at the time of injury onset halted the progression of fibrosis in both the kidney and the KLN. These findings for the first time highlight the association between fibrosis both in the kidney and the KLN during UUO, and they lay the groundwork for future studies that will investigate more deeply the mechanisms behind the connection between FRCs and KLN fibrosis.

SP5.1.11 The immune landscape of the Tumour draining lymph node and the Tumour Microenvironment in oesophageal; A novel therapeutic target

Aim The tumour microenvironment (TME) and tumour-draining lymph node microenvironment (LNME) remain poorly understood. Our study profiles the immune, angiogenic and inflammatory environment of the LNME and the TME of oesophagogastric patients. Methods The prognositc value of nodal status, clinical stage and tumour regression grade (TRG) was evaluated using a cohort of OAC patients (n = 702). Immune checkpoints (ICs) on tumour-draining lymph nodes(TDLNs, n = 6) and tumour tissue(n = 9) at surgical resection was assessed by flow cytometry. We also screened for cytokines, angiogenic mediators and chemokines. Using The Cancer Genome Atlas (TCGA), protein and mRNA levels (n = 72) and mutated versus non-mutated copies(n = 87) of this panel was correlated with survival. Results The frequency of CD3+TIM-3 and PD-1+T cells in TDLNs positively correlated with clinical tumour status as did CD8 + PD-1+TIGIT + T cells with nodal burden. Pro-angiogenic factor bFGF was significantly higher within the TME compared with the LNME. PIGF and SAA mediators of tumour growth were significantly higher in the LNME and levels of SAA in LNME positively correlated with adverse features. High levels of pro inflammatory IL-8,IL-6 and Flt1, mutations in pro-inflammatory genes CCL26,IL-31 and IL-17C and anti-tumour IL-1RN and CCL22 correlated with reduced overall survival. Conclusions The TME is more immunosuppressive than the TDLN, however, certain pro-angiogenic factors were enriched in TDLNs suggesting the priming of a pre-metastatic niche. Given the association of ICs with clinical features and tumour biology this may help to inform novel therapeutic approaches.

Directing an mRNA-LNP vaccine toward lymph nodes improves humoral and cellular immunity against SARS-CoV-2

The exploration and identification of safe and effective vaccines for the SARS-CoV-2 pandemic has captured the world’s attention and remains an ongoing issue in order to protect against emerging variants of concern (VoCs) while generating long lasting immunity. Here, we report the synthesis of a novel messenger ribonucleic acid (mRNA) encoding the spike protein in a lipid nanoparticle formulation (LNP) (STI-7264) that generates robust humoral and cellular immunity following immunization of C57Bl6 mice. In efforts to continually improve immunity, a lymphatic drug delivery device (MuVaxx) was engineered and tested to modulate immune cells at the injection site (epidermis and dermis) and draining lymph node (LN) to elicit adaptive immunity. Using MuVaxx, immune responses were elicited and maintained at a 10-fold dose reduction compared to traditional intramuscular (IM) administration as measured by anti-spike antibodies, cytokine producing CD8 T cells, and neutralizing antibodies against the Washington (Wild Type, WT) and South African (beta) variants. Remarkably, a 4-fold elevated T cell response was observed in MuVaxx administered vaccination as compared to that of IM administered vaccination. Thus, these data support further investigation into STI-7264 and lymphatic mediated delivery using MuVaxx for SARS-CoV-2 and VoCs vaccines.

TGF-[beta]-dependent Lymphoid Tissue Residency of Stem-like T cells Limits the Response to Tumor Vaccine

Stem-like CD8+ T cells represent the key subset responding to multiple tumor immunotherapies, including tumor vaccination. However, the signals that control the differentiation of stem-like T cells are not entirely known. Most previous investigations on stem-like T cells are focused on tumor infiltrating T cells (TIL). The behavior of stem-like T cells in other tissues remains to be elucidated. Tissue-resident memory T cells (TRM) are often defined as a non-circulating T cell population residing in non-lymphoid tissues. TILs carrying TRM features are associated with better tumor control. Here, we found that stem-like CD8+ T cells differentiated into TRMs in a TGF-β and tumor antigen dependent manner almost exclusively in tumor draining lymph node (TDLN). TDLN-resident stem-like T cells were negatively associated with the response to tumor vaccine. In other words, after tumor vaccine, TDLN stem-like T cells transiently lost TRM features, differentiated into migratory effectors and exerted tumor control.

Injectable Nanoparticle-Based Hydrogels Enable the Safe and Effective Deployment of Immunostimulatory CD40 Agonist Antibodies

When properly deployed, the immune system can render deadly pathogens harmless, eradicate metastatic cancers, and provide long-lasting protection from diverse diseases. However, realizing these remarkable capabilities is inherently risky, as disruption to immune homeostasis can lead to dangerous complications and autoimmune disorders. While current research is continuously expanding the arsenal of potent immunotherapeutics, there is a technological gap when it comes to controlling when, where, and how long these drugs act on the body. Here, we explored the ability of a slow-releasing injectable hydrogel depot to reduce the problematic dose-limiting toxicities of immunostimulatory CD40 agonist antibodies (CD40a) while maintaining their potent anti-cancer efficacy. We previously described a polymer-nanoparticle (PNP) hydrogel system that is biocompatible, long lasting, and injectable, traits that we hypothesized would improve locoregional delivery of the CD40a immunotherapy. Using PET imaging, we found that hydrogels significantly improve CD40a pharmacokinetics by redistributing drug exposure to the tumor and the tumor draining lymph node (TdLN). Consistent with this altered biodistribution, hydrogel delivery significantly reduced weight loss, hepatotoxicity, and cytokine storm associated with treatment. Moreover, CD40a-loaded hydrogels were able to mediate improved local cytokine induction in the TdLN and improve treatment efficacy in both mono- and combination therapy settings in the B16F10 melanoma model. These results suggest that PNP hydrogels are a facile, drug-agnostic method to ameliorate immune-related adverse effects and explore locoregional delivery of immunostimulatory drugs.